The present invention relates to a prepreg including a fiber base material layer containing a fiber base material, a first resin layer formed on one surface of the fiber base material layer, and a second resin layer formed on the other surface of the fiber base material layer, wherein the first resin layer is a layer obtained through layer formation of a resin composition (I) containing, as a main component of resin components, an epoxy resin (A), and the second resin layer is a layer obtained through layer formation of a resin composition (II) containing, as a main component of resin components, an amine compound (B) having at least two primary amino groups in one molecule thereof and a maleimide compound (C) having at least two N-substituted maleimide groups in one molecule thereof; a laminated sheet obtained by using the prepreg; a printed wiring board; a coreless board; a semiconductor package; and a method of producing a coreless board.

The present disclosure relates to a halogen-free epoxy resin composition and a prepreg and a laminate using the same. The halogen-free epoxy resin composition comprises: (A) a halogen-free epoxy resin; (B) an active ester resin; and (C) a reactive phosphorous-containing flame retardant. The prepreg and laminate made from the halogen-free epoxy resin composition have the advantages of high inter-laminar adhesive force, low coefficient of thermal expansion and high heat-humidity resistance, and can achieve the halogen-free flame retardant purpose.

Varnish compositions and prepregs and laminates made therefrom wherein the varnish compositions include at least one first epoxy resin and at least one second epoxy resin that includes a bisphenol-A novolac epoxy resin and a harder wherein the at least one first epoxy resin and the at least one second bisphenol-A novolac epoxy resin are present in the varnish at a weight ratio ranging from about 1:1 to about 1:3.

The resin composition includes: an epoxy resin as Component (A); a phenolic compound as Component (B); and an imidazole compound having a triazine skeleton, as Component (C). A cured product of the resin composition has a glass transition temperature of 260 C. or more.

A curable composition includes specific amounts of a ketone, a curable component, and particulate poly(phenylene ether) having a mean particle size of 3 to 12 micrometers and a particle size relative standard deviation of 20 to 60 percent. The composition has a low viscosity that facilitates wetting of reinforcing structures, and composites formed from the composition and a reinforcing structure cure to form a dielectric material with a low dielectric constant and loss tangent.

Provided are an epoxy resin composition including hexagonal boron nitride particles having an aspect ratio of 2 or more, a liquid crystalline epoxy monomer, and a curing agent, and the epoxy resin composition being capable of forming a resin matrix having a smectic domain by reacting the liquid crystalline epoxy monomer with the curing agent, and a thermally-conductive material precursor, a B-stage sheet, a prepreg, a heat dissipation material, a laminate, a metal substrate, and a printed circuit board, which use the epoxy resin composition.

Provided is a resin composition that has satisfactory impregnability into reinforcing fibers due to low viscosity and small viscosity increase even in an impregnation process performed for a long time. The resin composition being suitable as a matrix resin for a fiber-reinforced composite material for producing a cured molded article that has toughness and fatigue resistance. The resin composition for a fiber-reinforced composite material includes an epoxy resin, an acid anhydride-based curing agent, an imidazole-based curing accelerator, a radically polymerizable monomer, and a radical polymerization initiator as essential components, has a viscosity at 25 C. that falls within a range of 50 mPa.Math.s to 800 mPa.Math.s as measured by an E-type viscometer, and exhibits a viscosity increase ratio of 200% or less after 8 h at 25 C., wherein 50% by mass or more of the acid anhydride-based curing agent is an alicyclic acid anhydride having no olefinic unsaturated bond.

The present invention provides a thermosetting resin composition comprising (A) a metal salt of disubstituted phosphinic acid, (B) a maleimide compound having a N-substituted maleimide group in a molecule, (C) a 6-substituted guanamine compound or dicyandiamide and (D) an epoxy resin having at least two epoxy groups in a molecule and a prepreg and a laminated plate which are prepared by using the same. The prepregs obtained by impregnating or coating a base material with the thermosetting resin compositions of the present invention and the laminated plates produced by laminating and molding the above prepregs are balanced in all of a copper foil adhesive property, a glass transition temperature, a solder heat resistance, a moisture absorption, a flame resistance, a relative dielectric constant and a dielectric loss tangent, and they are useful as a printed wiring board for electronic instruments.

The present disclosure relates to a halogen-free epoxy resin composition and a prepreg and a laminate using the same. The halogen-free epoxy resin composition comprises: (A) a halogen-free epoxy resin; (B) an active ester resin; and (C) a reactive phosphorous-containing flame retardant. The prepreg and laminate made from the halogen-free epoxy resin composition have the advantages of high inter-laminar adhesive force, low coefficient of thermal expansion and high heat-humidity resistance, and can achieve the halogen-free flame retardant purpose.

Provided is a resin composition for forming a resin layer of a laminate by coating, the resin composition having a thixotropic index at 25 C. of from 3 to 10, and the laminate includes a pair of members and the resin layer arranged between the pair of members.